Overhead traveling sandslinger

ABSTRACT

An overhead traveling sandslinger for the production of relatively large molds in foundries, comprising a transversely movable carriage on an overhead traveling frame structure, a slinger liftably and revolvably suspended from said transversely movable carriage, the arrangement being such that the traveling movement of said frame structure, the transverse movement of said carriage and the lifting and revolving movements of said slinger cooperate with each other so that flask molding can be effected with respect to a flask disposed at any place within an area in a foundry without moving the flask. Molding sand is supplied to the slinger through the components of the apparatus.

0 United States Patent [151 3,674,129 Ikuo et al. July 4, 1972 [54] OVERHEAD TRAVELING 3,471,041 10/1969 Parsons ..2l4/17 C SANDSLINGER Primary ExaminerRobert G. Shendan [72] Inventors: Yorio lkuo; Minoru Okabayashi; Keisuke A Fa F t and Farley Ono; Yoshikazu Mizugaki; Juntaro Hayashi, all of Osaka, Japan I 57 ABSTRACT Assigncci imncni Shipbuilding and Engineering w An overhead traveling sandslinger for the production of rela- Ltd. tively large molds in foundries, comprising a transversely [22] Filed; No 6, 1970 movable carriage on an overhead traveling frame structure, a

slinger liftably and revolvably suspended from said transverse- PP 871466 ly movable carriage, the arrangement being such that the traveling movement of said frame structure, the transverse 52 US. Cl ..198/44, 164/199 198/100 movement 0f Said carnage and the lifting and 19 101 198/128 ments of said slinger cooperate with each other so that flask 51 1 1m. 01 ..B65g 37 00 molding can be effected with respect to a flask disposed at y 58 Field of Search ..214/10, 17c, 17CA, 17CB; Place within an area in foundry without moving the flask- 193/44 45 33 101 103 128 183; 1 4 199 Molding sand is supplied to the slinger through the components of the apparatus. [56] References Cited UNITED STATES PATENTS 11 Claims, 11 Drawing Figures 1,816,000 7/1931 Beardsley et al ..l64/l99 PKTENTEDJUL "'4 1912 SHEET 2 OF 9 PATENIEnJuL' 4 1972 3.674.129

SHEET 5 (IF 9 PHENTEDJUL 4 I972 3, 6 74, 129

SHEET 7 or 9 FIG.8

FIG."

PATENTEDJUL 4 I972 3.674.129

saw a or 9 ll Y dlltl lllliw OVERHEAD TRAVELING SANDSLINGER BACKGROUND OF THE INVENTION Recently, in a foundry where large castings are produced, it has become common practice to use a sandslinger to save labor. The conventional sandslingers may be classified roughly into two types, namely the stationary type and the mobile type. In the former type, the sandslinger is disposed at a fixed place and flask molding is effected by bringing the flask into the range of mobility of the sandslinger arm and upon completion of flask molding, the flask is carried away to another place. That is to say, the sandslinger is fixed in position while flasks are carried from place to place. In the latter type, the sandslinger is movable on rails or guides laid along the foundry building structure so that flask molding can be efiected without moving flasks which are placed within the range of mobility of the sandslinger. The latter mobile type is advantageous over the former stationary type in that it has a wider range of mobility. However, the mobile type has the disadvantage that the installation costs are high, and, moreover, it is impossible to enlarge the range of mobility of the sandslinger so as to cover the entire area of the foundry. Since the conventional mobile type is limited in the range of mobility by the rails or guides, in a foundry of large span it is impossible to effect flask molding with flasks placed outside the range of the length of the slinger arm. Therefore, it is necessary to convey flasks placed outside the range of the arm of the slinger arm, but in the case of large flasks, such conveying operation has to resort to the use of a crane. As a result, in connection with the shape of flasks or the place of installation of flasks, not only is additional labor required for the conveyance of flasks but also inconveniences are often caused to other molding operations.

The present invention has been accomplished to eliminate disadvantages including those described above, and provides an overhead traveling sandslinger superior in mobility which is capable of being moved to any place within a large area of a foundry and easily effecting flask molding without moving flasks.

SUMMARY OF THE INVENTION An overhead traveling sandslinger according to the present invention comprises an overhead traveling frame structure, a transversely movable carriage capable of traveling on said overhead traveling frame structure in a direct transverse to the direction of travel of said frame structure, a slinger suspended from said transversely movable carriage through suspension means, said slinger comprising a ramming head, a conveyor for feeding molding sand to said head, and a hopper for feeding molding sand into said conveyor.

When the present sandslinger having the features described above is used, it is possible to move the slinger to any place within an area of the foundry through the traveling movement of the overhead traveling frame structure and the movement of the transversely movable carriage, so that flask molding can be efficiently effected without moving flasks. This mobility of the present sandslinger is decidedly superior to the conventional mobile type which moves along rails or guides.

Moreover, the present sandslinger may be constructed by a simple and easy remodeling of an existing overhead traveling crane, including removing the hoist to utilize the crane girder as a traveling frame structure and attaching a main hopper and a suspension device for the slinger to the transversely movable carriage on the crane girder. It is possible not only to utilize the electric power source of the conventional overhead traveling crane for the present sandslinger, but also to remotely control by a single operator all motor operations including the traveling of the overhead traveling frame structure, the transverse movement of the transversely movable carriage, the raising and lowering of the slinger, and the operation of the conveyor, simply by attaching a control panel to the ramming head. If the sandslinger becomes unnecessary, it may be relatively easily converted back into the original overhead traveling crane.

Further, there is proposed an arrangement wherein as a means for continuously feeding molding sand into the hopper of the slinger, a relay conveyor capable of conveying molding sand is installed on the overhead traveling frame structure throughout the length of the path of travel of the transversely movable carriage and a scraper is attached to the transversely movable carriage whereby the molding sand being conveyed by said conveyor is scraped off onto the caniage.

If these means are provided in the present sandslinger, the necessity of storing a large amount of molding sand in the main hopper of the transversely movable carriage and in the hopper of the slinger main body is eliminated, with the advantage of decreasing the amount of material in the structural members of the traveling frame structure and transversely movable carriage.

Other features, functions and advantages of the invention will be fully understood from the following description of the embodiments illustrated in the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation showing one form of an overhead traveling sandslinger according to the invention;

FIG. 2 is a plan view of part of the sandslinger shown in FIG.

FIG. 3 is an enlarged fragmentary elevation of the slinger, the suspension means and the molding sand feed means shown in FIG. 1;

FIG. 4 is an enlarged sectional elevation of the line 4-4 of FIG. 1;

FIG. 5 is an enlarged sectional plan view on the line 5-5 of FIG. 1;

FIG. 6 is an elevation showing another form of an overhead traveling sandslinger according to the invention with a relay conveyor for molding sand mounted on an overhead traveling frame structure;

FIG. 7 is a fragmentary plan view of the sandslinger shown in FIG. 6;

FIG. 8 is an enlarged sectional elevation on the line 88 of FIG. 6;

FIG. 9 is an enlarged sectional elevation of molding sand feed means having a sand feed conduit formed of two relatively slidable tubes;

FIG. 10 is an enlarged sectional elevation showing the molding sand feed means and the lifting means for raising and lowering the slinger constituting the suspension means shown in FIG. 9; and

FIG. 1 I is a composite sectional plan view on the lines 11- I1 and I1l1' ofFlG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment This embodiment is shown in FIGS. 1-5, wherein, the numeral 2] denotes an overhead traveling frame structure supported at the opposite ends thereof by wheels 24 riding on rails 23 laid on a building frame 22. A motor 25 mounted on the frame structure 2] drives the wheels 24 through the intermediary of a transmission gearing 26 and a shaft 27, thereby causing the frame structure 21 to travel along the rails 23.

Laid on the upper surface of the frame structure 21 are two transverse rails 28, on which the wheels 30 of a transversely movable carriage 29 are supported. A motor 31 mounted on the transversely movable carriage 29 drives the wheels 30 through suitable gearing 32, thereby causing the transversely movable carriage 29 to be moved on the frame structure 21 along the rails 28.

A hollow fixed column 32 is suspended from and firmly secured to the lower surface of the transversely movable carriage 29 by means of a support member 33, as shown in FIGS. 1 and 4, the fixed column having a rack 34 and a guide groove 35 both cut in the lower surface thereof along a predetermined length. A main hopper 36 is mounted on the transversely movable carriage, and an expansible sand feed tube 37,

formed of a bellows tube, is inserted in the fixed column 32 and is connected to the lower end of the main hopper 36 and to a discharge tube 38. As shown in FIG. 4, the main hopper 36 is provided at the bottom with a movable plate 39 operable by a handle 40 to regulate the discharge of the molding sand contained in the main hopper 36. The discharge tube 38, as shown in FIGS. 1 and 3, projects outwardly through a guide slot 41 cut in the fixed column along a length thereof corresponding to the amount of expansion of the sand feed tube 37, and is provided with a guide element 42 engaging the fixed column so that the discharge tube 38 can be smoothly raised and lowered along the guide slot or opening 41 as the sand feed tube 37 retracts and extends. Further, the opposed sides of the guide opening 41 in the fixed column 32 are provided with reinforcing plates 43 (FIG. which serve both as a means of compensating for the loss in the strength of the fixed column due to the cutting of the guide opening 41 therein and as a guide for the discharge tube 38.

A movable column 44 is slidably fitted on the fixed column 32 and provided at the upper side thereof with a bracket 45 (FIG. 3) on which a reduction geared motor 46 is mounted for raising and lowering operations, the movable lifting column being further provided at the intermediate outer periphery thereof with an annular hopper 47. The lower end of the movable column 44 is fitted in a revolving drum 48 rotatably supported by bearings 49 and 50 disposed one above the other. A pinion 51 for revolving operation is fixed to the movable column 44.

Opposite surfaces of said movable column 44 are provided with keys 52 slidably fitted in the guide grooves 35 cut in the lateral surface of the fixed column 32, so that the lifting column 44 can be raised and lowered along the fixed column 32 without being rotated. Thus, the raising and lowering of the movable column 44 is efi'ected by the reduction geared motor 46 through a pinion 54 meshing with the rack 34 cut in the lateral surface of the fixed column 32, and the revolving drum 48 mounted on the lower portion of the movable column is also raised and lowered along the fixed column 32.

The numeral 55 denotes a slinger, which, as shown in FIGS. 1 and 2, comprises a jib am 56 fixed to the revolving drum 48, a ramming arm 58 connected to said arm 56 through a pivoted block 57, a ramming head 60 mounted on the front end of the arm 58 for slinging molding sand into a flask 59, an operator's seat 61, an operation panel 62, the previously mentioned annular hopper 47, and a jib conveyor 63 and a ramming conveyor 64 for feeding the molding sand delivered from the hopper 47 into the ramming head 60. The operation panel 62 is provided with controls for the traveling of the frame structure 21, the transverse movement of the carriage 29, the lifting and revolving of the slinger main body 55, etc. The jib arm 56 includes a fluid cylinder 66 for reciprocating a rack 65 meshing with said pinion 51 thereby to revolve the jib arm 56 and hence the ramming head 60 around the axis of the movable column 44; and, a fluid cylinder 69 (FIG. 2) for reciprocating a rack 68 meshing with a pinion 67 mounted on said pivoted block 57 so as to be rotated along with said ramming arm 58 thereby to revolve the ramming arm 58 and hence the ramming head 60 around the axis of the block 57. The numeral 70 denotes a reduction geared motor for said jib conveyor 63; the numeral 71, a sling shaft; and the numeral 72 denotes a cover for the rack rod 65.

A hopper bottom plate 73 (FIGS. 1 and 3) is rotatably fitted around the periphery of the movable column 44 adjacent the lower end of the annular hopper 47. The hopper bottom plate 73 is integral with an inlet guide plate 74 for the jib conveyor 63 of the slinger 55 and is adapted to revolve along with the arm 56 of the slinger 55.

That portion of the hopper bottom plate 73 which is communicatable with the inlet guide plate 74 is provided with a molding sand discharge port 75 cut therein so that even if the arm 56 of the slinger main body is revolved in either direction, the molding sand stored in the annular hopper 47 can always be fed correctly onto the jib conveyor 63. Further, an annular elastic member 76 such as of rubber is provided between the annular hopper 47 and the hopper bottom plate 73 to prevent the leakage of sand through the clearance therebetween.

A sand diverter 77, shown at the upper right hand portion of FIG. 1, is mounted on a support rod 78 erected at the end of the traveling frame structure and can be raised and lowered. When the diverter 77 is lowered, molding sand being conveyed on a molding sand refilling conveyor 79 installed along the building frame 22 is fed into the main hopper 36 on the transversely movable carriage 29 through a chute 80.

As described above, the means for feeding the molding sand contained in the main hopper 36 mounted on the transversely movable carriage 29 into the annular hopper 47 of the slinger 55 comprises the sand feed tube 37 and the discharge tube 38. Further, means for suspending the slinger 55 from the transversely movable carriage 29 comprises the support member 33, the hollow fixed column 32, the movable column 44, and the revolving drum 48. The means for raising and lowering the movable column 44 with respect to the fixed column 32 comprises the rack 34 on the fixed column 32, the pinion 54 provided on the lifting column 44, the transmission gearing 53 and the reduction geared motor 46. The means for revolving the slinger 55 around the axes of the fixed and movable columns 32 and 44 comprises the pinion 51 fixed to the lower portion of the movable column 44, the rack 65 meshing therewith, the fluid cylinder 66 for moving said rack rod 65, and the jib arm 56 mounting said cylinder 66 thereon and fixed to the revolving drum 48.

The overheadtraveling sandslinger in this embodiment is constructed in the manner described above. The operation thereof will now be described.

When it is desired to feed molding sand into the ramming head 60 of the slinger main body, the operator manipulates the corresponding control on the operation panel 62 to move the transversely movable carriage 29 to the end of the frame structure 21, so that at the position shown in broken lines in FIG. 1, the molding sand conveyed on the molding sand refilling conveyor 79 installed along the building frame 22 is discharged into the main hopper 36 through the chute 80 by lowering the diverter 77. Thereafter, by switch operation of controls on the panel 62, the traveling of the frame structure 21 and the transverse movement of the carriage 29 are effected to move them to a place in the vicinity of the flask 59. If the flask is located on a high level, the lifting reduction geared motor 46 is actuated to rotate the pinion 54 meshing with the rack 34, thereby raising the movable column 44 as indicated in broken lines in FIG. 1.

When the preparatory operation has thus been completed, the plate 39 of the main hopper 36 of the transversely movable carriage 29 is opened by the operation of the handle 40. As a result of this operation, the molding sand is fed into the annular hopper 47 from the discharge tube 38 through the sand feed pipe 37 and is then fed onto the jib conveyor 63 through the discharge port 75. At the same time, the jib conveyor 63, the ramming conveyor 64 and the ramming head 60 are actuated, so that as shown in FIG. 2 while the arms 56 and 58 are being moved the molding sand is slung into the flask 59 to effect flask molding. If the arm 56 is moved, the hopper bottom plate 73 disposed at the lower end of the annular hopper 47 is also moved, so that the molding sand can always be fed onto the jib conveyor 63 through the discharge port 75 and there is no danger of interrupting the operation of the slinger. Further, since the sand feed tube 37 is capable of expansion and contraction as it is formed of a bellows tube of elastic material such as rubber or synthetic resin, it extends and reacts in response to the lowering and raising of the movable column 44 so that there is no interruption of the feeding of the molding sand.

With regard to the raising and lowering movements of the slinger 55, it is also possible to attain the same raising and lowering as described above without resorting to the rack 34 and the pinion 54 shown in this embodiment but instead by using fluid pressure cylinder means or by providing the transversely movable carriage with hoist means to produce the up and down movements. Further, in this embodiment the discharge tube 38 has been shown as not fixed to the movable column 44, but even if they are fixed together the same function as described above can be attained.

Second Embodiment This embodiment, shown in FIGS. 6-8 is a modification of the first embodiment, wherein means is additionally provided whereby, no matter where the transversely movable carriage is positioned along the overhead traveling frame structure, molding sand can be continuously fed into the main hopper installed on the transversely movable carriage from the molding sand refilling conveyor installed along the building frame. Thus, in this embodiment, the other arrangements, namely, the slinger, the suspension means for the slinger the molding sand feed means, etc. are the same as those in the first embodiment, and therefore they have the same reference numerals as used in the first embodiment with the prime added thereto.

Those features of this embodiment by which it is differentiated from the first embodiment will now be described.

An overhead traveling frame structure 101 is equipped with a relay conveyor 106 for feeding the molding sand from a molding sand refilling conveyor installed along a building frame 102 directly into a main hopper 105 installed on a transversely movable carriage 104. The conveyor 106 comprises a conveyor belt 107 extending along substantially the entire length of said frame structure 101 between a driving pulley 108 and an idler pulley 109 disposed at opposed ends of the frame structure 101; the driving pulley 108 being driven from a reduction geared motor 110 through a sprocket wheel 112 fixed on a driving shaft 111, and the idler pulley being supported by take-up bearings 113. The numeral 114 denotes a bracket erected on the transversely movable carriage 104 and the numerals 115 and 1 16 respectively denote a scraper and a chute, supported by the bracket 114, and arranged so that the molding sand conveyed on the conveyor belt 107 is scraped off into the chute 116 by the scraper 115 and fed into the main hopper 105.

In the slinger of this embodiment equipped with the above mentioned means, since when the transversely movable carriage I04 moves transversely, the scraper 115 also travels freely on the conveyor belt 107 installed along substantially the entire length of the frame structure 101, the molding sand can be fed into the main hopper 105 no matter where the transversely movable carriage 104 is positioned, and in accordance with the operation of the slinger the necessary molding sand can be continuously admitted into the ramming head 60. Therefore, there is no need to store molding sand in the main hopper 105 of the transversely movable carriage 104, so that the main hopper 105 can be made as small as possible and accordingly there are advantages including the possibilities of decreasing the loads on the transversely movable carriage and of reducing the structural materials used for the transversely movable carriage 104 and the frame structure 101.

Third Embodiment This embodiment is shown in FIGS. 9-11 and is adapted to make it possible to attain a very smooth movement without any loss of force due to eccentricity, etc., in the raising, lowering and revolving of the slinger.

When compared with the first embodiment, this embodiment is different therefrom mainly in that the molding sand feed conduit of the molding sand feed means is constructed by using two telescopically fitted tubes and that the slinger lifting means is constructed by using an oil pressure cylinder device. The other arrangements, i.e., the overhead traveling frame structure, the transversely movable carriage, the slinger, etc. are the same as those of the first embodiment, and most of the parts that are the same as those of the first embodiment are omitted in the Figures.

In FIG. 9, the numeral 201 denotes a transversely movable carriage which moves transversely on the overhead traveling frame (not shown); the numeral 202, a reinforcing member rigidly secured to said transversely movable carriage; the numeral 203, a hollow fixed column fixed to and suspended from said reinforcing member and provided, as shown in FIG. 10, with a guide groove 204 cut in the lateral wall thereof along a necessary length; the numeral 205, a movable column slidably fitted on said fixed column 203 and having a key 206 fixed on the inner surface thereof and fitted in said guide groove 204 so that the movable column can be raised and lowered along the fixed column 203 without being rotated; the numeral 207, a main hopper fixed to said transversely movable carriage and provided at its bottom with a predetermined length of inner sand feed tube 208; and the numeral 209 denotes an outer sand feed tube in which said inner sand feed tube 208 is fitted. The lower portion of the outer sand feed tube is provided with a discharge tube 210, which projects beyond said fixed column through a guide slot 211 out in the lifting column 205 along a sufficient length to permit the raising and lowering of the movable column. The bottom surface of the portion of the discharge tube 210 positioned within the fixed column 203 is provided with a weight 212, so that when the movable column reaches its lower limit of movement, the discharge tube 210 will be supported on the lower end of the guide slot 211 under the action of the weight 212 plus the weight of the discharge tube. The lower end of the discharge tube 210 may be fixed to the upper end of the movable column 205.

The numeral 213 (FIG. 10) denotes a piston rod extending downwardly from the lower end of the fixed column 203 through the lower end wall of the movable column 205, and fitted to the piston 215 of an oil pressure cylinder 214 formed integrally and coaxially with the movable column 205. The lower end of the oil pressure cylinder is sealed with a cover 216. Oil charging and discharging ports 217 and 218 connect with the cylinder at upper and lower levels and with oil charging and discharging tubes 219 and 220 from an oil pressure pump (not shown).

An annular hopper 221, shown in FIG. 10, is provided coaxially around the outer periphery of the movable column 205 and is fixed thereto by a plurality of ribs 222. A hopper bottom plate 223, mounted on a revolving drum 224, is positioned adjacent the lower end surface of the annular hopper 221 and loosely fitted on the outer periphery of the lifting sleeve 205. Further, as shown in FIGS. 10 and 11, the hopper bottom plate 223 is formed with a discharge port 225, and an adjusting plate 227 for adjusting the amount of discharge of molding sand is slidably fitted in a guide 226 provided on the lower surface of the hopper bottom plate 223. The hopper bottom plate 223 is provided with a guide plate 228 disposed below the discharge port 225, and a bracket 229 projecting from the hopper bottom plate 223 pivotally mounts thereon a lateral guide 233 for the jib conveyor 231 of a slinger, thereby ensuring that the molding sand discharged through the discharge port 225 is reliably fed onto the upper surface of a conveyor belt 240'. An annular elastic member 234 is fitted around the outer periphery of the lower end portion of the annular hopper 221 to prevent the leakage of molding sand.

As shown in FIG. 10, the oil pressure cylinder 214 formed at the lower portion of the movable column 205 is inserted in the revolving drum 224 with a clearance therebetween. A tapered roller bearing 235 is fitted in the upper region of said clearance and held in position by a ring 236 screwed on the oil pressure cylinder 214, and a taper roller bearing 237 is fitted in the lower region and held in position by a bearing cover 238, so that both radial and thrust loads on the revolving drum 224 are borne by the oil pressure cylinder 214. A pinion 239 fixed to the outer periphery of the oil pressure cylinder meshes with a rack 240 connected to the piston rod 242 of a fluid cylinder (not shown) mounted on a jib arm of the slinger 230, so that when the fluid cylinder is actuated, the slinger will rotate around the axis of the oil pressure cylinder 214 and hence around the axis of the movable column 205.

The lower end of the discharge tube 210 is provided with a bracket 243 pivotally supporting a shaft 244 (FIG. 11) which carries a valve plate 245 and a handle 246. A guide plate 247, projecting outwardly from the outer surface of the lateral wall of the discharge tube 210, has an arcuate groove cut therein in which is fitted a screw projection 248 provided on the handle 246, so that the degree of opening of the valve plate 245 can be adjusted and maintained by moving the handle 246 along the guide plate 247 until a desired position is reached whereupon a thumb nut 249 screwed on said projection 248 is tightened.

A motor pulley 250 for driving the conveyor belt 240' of the jib conveyor of the slinger 230 is mounted on a support arm 251 projecting from the revolving drum 224 together with fluid cylinder 252, for revolving the jib arm of the slinger 230, pivotally connected to the support arm 251 by a pin 253. The numeral 254 denotes a cover for the rack 240 and the numeral 255 denotes an oil pressure pump case for the fluid cylinder, which case is mounted on the revolving drum 224.

As described above, in this embodiment, the molding sand feed means are composed of two telescopically fitted tubes 208 and 209 and the suspension means for the slinger includes the oil pressure cylinder 214 extending from the lower end of the movable column 205, the revolving drum 224 fitted on the cylinder 214, and the piston stem 213 connected to the lower end of the fixed column 203.

The operation of this embodiment will now be described. In order to raise the revolving drum 224 and hence the slinger 230, an oil pressure pump (not shown) is driven to feed working oil through the oil charging and discharging tube 219 at the upper portion of the oil pressure cylinder 214. Since the piston 215 extends from the fixed column 203 on the transversely movable carriage 201, the feeding of working oil through the oil charging and discharging tube 219 as described above causes the upper surface of the piston 215 to be pressurized, so that the relative positions of the fixed column 203 and cylinder 214 change from those shown in solid lines in FIG. 10 to those shown in broken lines and the slinger 230 is raised. in this case, although the discharge tube 210 is raised along the guide slot 21 l and inner sand feed tube 208 as shown in broken lines in FIG. 9, it is not rotated since rotation is prevented by the key way 204 and key 206 provided on the fixed and movable columns. However, the revolving drum 224 rotatably supported on the oil pressure cylinder 214 by the taper roller bearings 235 and 237 can be freely rotated around the axis of the lifting column 205 when the rack is moved.

The lowering of the revolving drum 224 and hence the slinger 230 is effected by feeding working oil into the oil pressure cylinder 214 through the tube 220 and the port 218 at the lower end portion of the oil pressure cylinder 214 so as to pressurize the lower surface of the piston 215, whereby the movable column 205 and hence the slinger are lowered along the fixed column 203. In this case, the lowering of the discharge tube 210 with the movable column 205 is achieved by the action of the weight of the tube plus the weight 212.

The operation of the molding sand feed means will now be described.

Molding sand supplied to the main hopper 207 of the transversely movable carriage 201 by conveyor means such as shown in the first and second embodiments is fed into the discharge tube 210 through the inner and outer sand feed tubes 208 and 209, is discharged as regulated by the valve plate 245, and is stored in the annular hopper 221. Subsequently, by adjusting the plate 227 at the discharge port 225 of the hopper bottom plate 223, a desired amount of molding sand is fed onto the conveyor belt 240' of the slinger 230 through the discharge port 225. No matter which direction the slinger and the revolving drum are rotated, the hopper bottom plate 223 revolves along with the revolving drum 224 to feed molding sand constantly onto the conveyor belt 240 through the discharge port 225, so that there is no trouble in the operation of the slinger. Further, since the discharge tube 210 communicates with the outer sand feed tube 209 within the fixed column 203 and moves up and down while sliding on the outer periphery of the inner sand feed tube 208 in response to the up and down movement of the movable column 205, there is no possibility of the feeding of molding sand being interrupted when the slinger is moved up or down. A uniform supply of molding sand is obtainable, since the amount of molding sand fed onto the conveyor belt 240' is adjusted by the valve plate 245 attached to the discharge tube 210 and by the discharge plate 227 installed at the discharge port 225 of the hopper bottom plate 223 in accordance with the amount of sand slung from the ramming head of the slinger. As for the raising and lowering of the lifting column, since the piston 215 is provided on the extension of the axis of the fixed column 203 and since the oil pressure cylinder 214 serves as the axis of the revolving drum 224, there is no loss of force due to eccentricity, etc., and not only is it possible to attain a very smooth up and down movement, but also the construction is simple and can be made compact.

The cross-section of the fixed column 203 may be polygonal instead of circular, such as triangular and hexagonal, while achieving the same merits as in this embodiment.

It will be understood from the above that the overhead traveling sandslinger of the present invention is capable of moving to any place within a large area of the foundry, so that flask molding can be effected without moving flasks, thus greatly increasing the efi'iciency of flask molding operations.

We claim:

1. An overhead traveling sandslinger comprising an overhead traveling frame structure; a movable carriage mounted on the frame structure and capable of traveling in a direction transverse to the direction of travel of said overhead traveling frame structure; a slinger; and means suspending the slinger from said transversely movable carriage; said slinger comprising a ramming head, a conveyor for feeding molding sand into said head, and a hopper for feeding molding sand onto said conveyor;

said means suspending the slinger comprising a column fixed to the transversely movable carriage, a movable column fitted to said fixed column for vertical movement with respect to the fixed column, lifting means for raising and lowering said movable column and a revolving means carried by the movable column for supporting the slinger so as to permit the latter to be revolved with respect to the fixed column.

2. An overhead traveling sandslinger as set forth in claim 1, wherein said lifting means comprises a rack fixed to one of said columns, a pinion supported by the other of said columns and meshing with said rack, and a motor for rotating said pinion.

3. An overhead traveling sandslinger as set forth in claim 1, wherein said lifting means includes a fluid pressure piston and cylinder connected between the fixed and movable columns and said revolving means is mounted for movement about the axis of said cylinder. I

4. An overhead traveling sandslinger as set forth in claim 1, wherein said revolving means includes a pinion fixed to the movable column so as to be coaxial therewith, a rack slidably supported by the slinger so as to be constantly meshing with said pinion, and cylinder means for reciprocating said rack.

5. An overhead traveling sandslinger as set forth in claim 1, wherein the hopper of the slinger main body is constructed in the form of an annular hopper coaxial with the axis of revolution of the slinger, said annular hopper having a discharge port disposed above and opposed to the conveyor of the slinger, and means for feeding molding sand including a discharge tube disposed above the annular hopper.

6. An overhead traveling sandslinger as set forth in claim 5, wherein the discharge tube of the molding sand feeding means projects outwardly from within the fixed column of the slinger suspending means through a vertically extending guide slot in said column and moves up and down concomitantly with the raising and lowering movement of the slinger a main hopper on the transversely movable carriage, and expansible conduit means disposed within said column and connecting the discharge tube to the main hopper.

7. An overhead traveling sandslinger as set forth in claim 6 wherein the expansible conduit means includes a bellows tube.

8. An overhead traveling sandslinger as set forth in claim 6 wherein the expansible conduit means includes two tubes which are telescopically fitted together.

9. An overhead traveling sandslinger as set forth in claim 6, wherein the annular hopper is provided with a hopper bottom plate which is separate therefrom and which has a discharge port at one place, said hopper being fixed to the movable column revolvably supporting the slinger, said hopper bottom plate being fixed to the slinger in such a manner that the discharge port of said hopper bottom plate is disposed above and opposed to the conveyor of the slinger, and means to prevent leakage between the hopper and the hopper bottom.

10. An overhead traveling sandslinger comprising an overhead traveling frame structure; a movable carriage mounted on the frame structure and capable of traveling in a direction transverse to the direction of travel of said overhead traveling structure; a slinger; means suspending the slinger from said transversely movable carriage; said slinger comprising a 11. An overhead traveling sandslinger as set forth in claim 10 wherein the means for diverting molding sand from the refilling conveyor to said main hopper includes a relay conveyor installed on the overhead traveling frame structure along the path of travel of the transversely movable carriage, and a scraper for guiding the molding sand from the relay conveyor to said main hopper. 

1. An overhead traveling sandslinger comprising an overhead traveling frame structure; a movable carriage mounted on the frame structure and capable of traveling in a direction transverse to the direction of travel of said overhead traveling frame structure; A slinger; and means suspending the slinger from said transversely movable carriage; said slinger comprising a ramming head, a conveyor for feeding molding sand into said head, and a hopper for feeding molding sand onto said conveyor; said means suspending the slinger comprising a column fixed to the transversely movable carriage, a movable column fitted to said fixed column for vertical movement with respect to the fixed column, lifting means for raising and lowering said movable column and a revolving means carried by the movable column for supporting the slinger so as to permit the latter to be revolved with respect to the fixed column.
 2. An overhead traveling sandslinger as set forth in claim 1, wherein said lifting means comprises a rack fixed to one of said columns, a pinion supported by the other of said columns and meshing with said rack, and a motor for rotating said pinion.
 3. An overhead traveling sandslinger as set forth in claim 1, wherein said lifting means includes a fluid pressure piston and cylinder connected between the fixed and movable columns and said revolving means is mounted for movement about the axis of said cylinder.
 4. An overhead traveling sandslinger as set forth in claim 1, wherein said revolving means includes a pinion fixed to the movable column so as to be coaxial therewith, a rack slidably supported by the slinger so as to be constantly meshing with said pinion, and cylinder means for reciprocating said rack.
 5. An overhead traveling sandslinger as set forth in claim 1, wherein the hopper of the slinger main body is constructed in the form of an annular hopper coaxial with the axis of revolution of the slinger, said annular hopper having a discharge port disposed above and opposed to the conveyor of the slinger, and means for feeding molding sand including a discharge tube disposed above the annular hopper.
 6. An overhead traveling sandslinger as set forth in claim 5, wherein the discharge tube of the molding sand feeding means projects outwardly from within the fixed column of the slinger suspending means through a vertically extending guide slot in said column and moves up and down concomitantly with the raising and lowering movement of the slinger a main hopper on the transversely movable carriage, and expansible conduit means disposed within said column and connecting the discharge tube to the main hopper.
 7. An overhead traveling sandslinger as set forth in claim 6 wherein the expansible conduit means includes a bellows tube.
 8. An overhead traveling sandslinger as set forth in claim 6 wherein the expansible conduit means includes two tubes which are telescopically fitted together.
 9. An overhead traveling sandslinger as set forth in claim 6, wherein the annular hopper is provided with a hopper bottom plate which is separate therefrom and which has a discharge port at one place, said hopper being fixed to the movable column revolvably supporting the slinger, said hopper bottom plate being fixed to the slinger in such a manner that the discharge port of said hopper bottom plate is disposed above and opposed to the conveyor of the slinger, and means to prevent leakage between the hopper and the hopper bottom.
 10. An overhead traveling sandslinger comprising an overhead traveling frame structure; a movable carriage mounted on the frame structure and capable of traveling in a direction transverse to the direction of travel of said overhead traveling structure; a slinger; means suspending the slinger from said transversely movable carriage; said slinger comprising a ramming head, a conveyor for feeding molding sand into said head, and a hopper for feeding molding sand onto said conveyor; a main hopper disposed on the transversely movable carriage; molding sand feed means for feeding molding sand from said main hopper into the hopper of the slinger; a molding sand refilling conveyor installed along the path of travel of the overhead traveling frame structure; and means for diverting molding sand from tHe refilling conveyor to said main hopper.
 11. An overhead traveling sandslinger as set forth in claim 10 wherein the means for diverting molding sand from the refilling conveyor to said main hopper includes a relay conveyor installed on the overhead traveling frame structure along the path of travel of the transversely movable carriage, and a scraper for guiding the molding sand from the relay conveyor to said main hopper. 